T cell responses to der f2 mite allergens in Thai allergic patients

Abstract

Dermatophagoides farinae group 2 (Der f2) is a highly polymorphic allergen that shows a distinct pattern of sequence divergence. The effect of the variants on antibody and T cell responses has not been compared. The aim of the present study was to evaluate IgE binding, transcription and translations for IL-5, IFN-γ and TGF-β induced by mite allergens. Sera from 24 HDM-allergic patients and 20 non-allergic subjects were measured for IgE reactivity by ELISA. PBMC was cultured with mite allergens (Df, rDerf2) and mitogen (PHA). The supernatants and cell pellet obtained were evaluated for cytokine production by ELISA and cytokine gene expression by RT-PCR, respectively. Four patients showed IgE reactivity to both allergens. Five patients showed IgE reactivity to Df. Other allergic patients and all non-allergic subjects did not show IgE reactivity to mite allergens. Both allergens showed similar levels of IL-5 and IFN-γ transcriptions in allergic patients and non-allergic subjects. The rDer f2 induced IL-5 protein from allergic patients higher than non-allergic subjects, while Df showed IL-5 protein from allergic patients similar to non-allergic subjects. Df induced IFN-protein from allergic patients higher than non-allergic subjects whereas rDer f2 induced IFN-protein from allergic patients similar to non-allergic subjects. The ratio of IFN-γ to IL-5 production after stimulation with rDer f2 was higher in non-allergic subjects than in allergic patients. Our data demonstrated that the changes in the sequence of rDer f2 compared with native Df had effect on cytokine production in both allergic patients and non-allergic subjects

Abundance of domestic mites in dwellings of children and adolescents with asthma in relation to environmental factors and allergy symptoms

“…Most often they are found in habitats intimately associated with humans, such as beds, couches, sofas, other upholstery furnitures, clothing, floors and carpets 4 , 7 , 9 , 10 , 29 . Two mite species D. pteronyssinus and D. farinae are most often found and most abundant in house dust throughout the world 4 , 7 , 9 , 10 , 12 , 14 , 19 , 29 . Laboratory culture studies showed that dust mites do not tolerate relative humidity below 60% (or 55% for D. farinae ) 1 – 3 , 5 , 12 , 30 – 33 .…”

“…Three species— Dermatophagoides pteronyssinus , Dermatophagoides farinae and Euroglyphus maynei— are reported to be the major allergen sources in house dust 9 , 12 – 16 . House-dust-mite allergens occurring in an indoor environment are the most important agents of respiratory diseases in humans, including asthma 17 – 19 .…”